The Bardet-Biedl syndrome is a a syndrome characterized mainly by obesity, pigmentary retinopathy, polydactyly, mental retardation, hypogonadism, and renal failure in fatal cases.

The syndrome is named after Georges Bardet and Arthur Biedl.

Two forms have been identified:

Bardet-Biedl syndrome 1 (BBS1) has no linkage to chromosome 16

Bardet-Biedl syndrome 2 (BBS2) is mapped to markers on chromosome 16.

Laurence-Moon-Biedl syndrome and Laurence-Moon-Biedl-Bardet syndrome are no longer considered as valid terms in that patients of Laurence and Moon had paraplegia but no polydactyly and obesity which are the key elements of the Bardet-Biedl the syndrome. Laurence-Moon syndrome is a separate entity.

Major features

Eyes: Pigmentary retinopathy.

Hand and foot: Polydactyly.

Cardiovascular system: Hypertrophy of interventricular septum and left ventricle and dilated cardiomyopathy.

Heredity: The syndrome is familial and is transmitted as an autosomal recessive trait. chromosome 3 locus appears to be linked to polydactyly of all four limbs, whereas chromosome 15 is associated with early-onset morbid obesity and is mostly confined to the hands, and chromosome 16 represents the "leanest" form.

Additional features: Obesity.

Cause

The detail biochemical mechanism that leads to BBS is still unclear. Recently, eight genes (BBS1 to BBS8) that are responsible for the disease when mutated have been cloned, and most of the gene products encoded by these BBS genes are located in the basal body and cilia of the cell. It has been postulated that these BBS gene products might involve in the cell signaling pathway in the cilia, and these signaling systems play an essential role in the normal development so that a malfunction in these systems causes the diverse pathological effects of the Syndrome.

STARS PUT ON THEIR JEANS TO BACK GENE RESEARCHTHE SEARCH for the defective genes which cause a rare debilitating syndrome has led to a discovery which could also provide clues to how obesity and ...From Evening Standard (London),
10/9/00
by ZOE MORRIS